Novel and unexpected stimuli are often prioritised in memory, given their inherent salience. Nevertheless, not all forms of novelty show such an enhancement effect. Here, we discuss the role expectation plays in modulating the way novelty affects memory processes, circuits, and subsequent performance. We first review independent effects of expectation on memory, and then consider how different types of novelty are characterised by expectation. We argue that different types of novelty defined by expectation implicate differential neurotransmission in memory formation brain regions and may also result in the creation of different types of memory. Contextual novelty, which is unexpected by definition, is often associated with better recollection, supported by dopaminergic-hippocampal interactions. On the other hand, expected stimulus novelty is supported by engagement of medial temporal cortices, as well as the hippocampus, through cholinergic modulation. Furthermore, when expected stimulus novelty results in enhanced memory, it is predominantly driven by familiarity. The literature reviewed here highlights the complexity of novelty-sensitive memory systems, the distinction between types of novelty, and how they are differentially affected by expectancy.

鉴于其固有的显着性，新奇和意想不到的刺激通常在记忆中被优先考虑。然而，并非所有形式的新颖性都显示出这种增强效果。在这里，我们讨论了期望在调节新颖性影响记忆过程、电路和后续性能的方式中所起的作用。我们首先回顾期望对记忆的独立影响，然后考虑不同类型的新颖性如何以期望为特征。我们认为，由期望定义的不同类型的新奇暗示记忆形成大脑区域的不同神经传递，也可能导致不同类型记忆的产生。上下文的新颖性，根据定义是出乎意料的，通常与更好的回忆有关，由多巴胺能-海马相互作用支持。另一方面，通过胆碱能调节，内侧颞叶皮层和海马体的参与支持了预期的刺激新颖性。此外，当预期的刺激新颖性导致记忆增强时，它主要是由熟悉程度驱动的。这里回顾的文献强调了对新奇敏感的记忆系统的复杂性、新奇类型之间的区别，以及它们如何受到预期的不同影响。